More Records of Sympatry of Black-faced Hawk (Leucopternis melanops) and White-browed Hawk (L. kuhli) in Madre de Dios, Peru

The Black-faced Hawk (Leucopternis melanops) and its sister species, the White-browed Hawk (L. kuhli), are both small (ca. 40 cm) forest hawks distinguishable only by subtle differences in plumage and call. They were once thought to be conspecifics and more recently have been thought to replace one another north (Black-faced Hawk) and south (White-browed Hawk) of the Amazon River (Ferguson-Lees and Christie 2001). Recent investigations revealed that these two species may be sympatric, and that Black-faced Hawk occurs irregularly south of the Amazon River (Raposo Do Amaral et al. 2007). Recently, two Black-faced Hawks were captured and photographed (Barlow et al. 2002) in the lower Tapajos River area, which is south of the Amazon River in Brazil; these captures were only 6 km from capture sites of Whitebrowed Hawk, documenting the sympatry of these species (Raposo Do Amaral et al. 2007). In 2006, we began an investigation to determine levels of mercury in raptors in gold-mining areas of Madre de Dios, Peru. We captured raptors using a bal-chatri trap and a live lure animal. Blood and feather samples were taken from each individual to analyze for mercury concentration. The raptors were then banded, photographed, and released. During the course of the investigation, three Black-faced Hawks and eight White-browed Hawks were captured. All captures occurred within 12 km of the Los Amigos Biological Station (12u34.159S, 70u6.009W) in similar mature upland forest. The Black-faced Hawks were captured on 4 June 2007, 15 July 2008, and 9 December 2009. The eight White-browed Hawks were captured between December 2006 and May 2009. The capture of these two species within a 12-km range in similar habitat further confirmed the occurrence of Black-faced Hawk in the range of Whitebrowed Hawk.